Pipe Fitting

Abstract

A multi-layer flexible pipe and method for making the same is disclosed. The multi-layer flexible pipe includes a barrier layer of polyamide-12 (PA-12) material.

1 . A multi-layer flexible pipe for conveying a target fluid, comprising:
 at least one barrier layer of polyamide-12 (PA-12), for providing internal fluid integrity.   
     
     
         2 . The multi-layer flexible pipe as claimed in  claim 1  further comprising:
 a core layer arranged to provide an inner bore along which a fluid can flow.   
     
     
         3 . The flexible pipe as claimed in  claim 1  or  claim 2  wherein the barrier layer has sufficient ductile and fracture toughness properties to ensure that the flexible pipe will be flexible enough to be located at a desired location and to perform adequately at that location for twenty or more years, for a given cumulative temperature and chemical exposure. 
     
     
         4 . The flexible pipe as claimed in  claim 3  wherein the barrier layer has a Corrected Inherent Viscosity of greater than 1.0 dl/g, for twenty or more years in operation, for a given cumulative temperature and chemical exposure. 
     
     
         5 . The flexible pipe as claimed in  claim 3  wherein the barrier layer has a Corrected Inherent Viscosity of greater than 1.2 dl/g, for twenty or more years in operation, for a given cumulative temperature and chemical exposure. 
     
     
         6 . The flexible pipe as claimed in  claim 5  wherein said barrier layer is an extruded layer. 
     
     
         7 . The flexible pipe as claimed in  claim 6  wherein said barrier layer is a variety of Polyamide-12. 
     
     
         8 . The flexible pipe as claimed in  claim 6  wherein said barrier layer is a Polyamide-12 modified with a flexibilising component 
     
     
         9 . The flexible pipe as claimed in  claim 8  wherein said flexililising component is a liquid plasticiser. 
     
     
         10 . The flexible pipe as claimed in  claim 9  wherein said plasticiser component is N-butylbenzenesulphonamide (BBSA). 
     
     
         11 . The flexible pipe as claimed in  claim 10  wherein said barrier layer is a layer of Degussa BS0725. 
     
     
         12 . The flexible pipe as claimed in  claim 10  wherein the barrier layer is a layer of Vestamid LX9020. 
     
     
         13 . The flexible pipe as claimed in  claim 1  wherein said barrier layer comprises a barrier polymer layer. 
     
     
         14 . The flexible pipe as claimed in  claim 1  wherein said target fluid comprises crude oil. 
     
     
         15 . The flexible pipe as claimed in  claim 13  wherein said target fluid comprises a gas. 
     
     
         16 . The flexible pipe as claimed in  claim 13  wherein said target fluid comprises export oil. 
     
     
         17 . The flexible pipe as claimed in  claim 1  wherein said barrier layer comprises a bore-fluid retaining layer. 
     
     
         18 . The flexible pipe as  claim 2 , wherein said barrier layer directly surrounds the core layer: 
     
     
         19 . The flexible pipe as claimed in  claim 1  wherein said multi-layer flexible pipe has three or more layers. 
     
     
         20 . The flexible pipe as claimed in  claim 1  wherein said barrier layer provides a layer with a high chemical resistance. 
     
     
         21 . The flexible pipe as claimed in  claim 1  wherein said flexible pipe comprises a non-bonded flexible pipe. 
     
     
         22 . The flexible pipe as claimed in  claim 1  wherein said core layer comprises a collapse-resistant layer. 
     
     
         23 . The flexible pipe as claimed in  claim 1  wherein said barrier layer comprises a fluid barrier layer. 
     
     
         24 . The flexible pipe as claimed in  claim 1  further comprising:
 at least one tensile strength layer; and   at least one external fluid barrier layer.   
     
     
         25 . The flexible pipe as claimed in  claim 1  wherein the barrier layer is an innermost polymer extruded layer located beneath a hoop strength layer. 
     
     
         26 . The flexible pipe as claimed in  claim 1  wherein the barrier polymer layer comprises one layer of a multi-layer barrier layer. 
     
     
         27 . The flexible pipe a claimed in  claim 26  wherein the multi-layer barrier layer comprises one or more layers of a further barrier material. 
     
     
         28 . The flexible pipe as claimed in  claim 1  wherein said barrier polymer layer has a melting point of more than 170c. 
     
     
         29 . A multi-layer flexible pipe for conveying a target fluid, comprising:
 at least one barrier polymer layer of polyamide-12, for providing internal fluid integrity.   
     
     
         30 . The multi-layer flexible pipe as claimed in  claim 1 , comprising:
 said barrier layer is formed from a polyamide-12 material formed from a process in which a salt of a weak acid is introduced during a step of condensing polyamides to increase the molecular weight to thereby nullify acid formed in an earlier stage.   
     
     
         31 . A method for providing a multi-layer flexible pipe for conveying a target fluid comprising the steps of:
 providing at least one barrier layer of polyamide-12 (PA-12) for providing internal fluid integrity.   
     
     
         32 . The method as claimed in  claim 31  further comprising the steps of:
 providing a core layer having an inner bore along which a target fluid can flow.   
     
     
         33 . The method as claimed in  claim 31  or  claim 32  further comprising the steps of:
 melting polyamide-12 in a food hopper;   providing the melted polymer at a crosshead chamber; and   forming a barrier layer of polyamide-12 in said crosshead.   
     
     
         34 . The method as claimed in  claim 33  further comprising the steps of:
 directing polyamide-12 from said feed hopper to said crosshead via a rotating screw and associated barrel.   
     
     
         35 . The method as claimed in  claim 34  further comprising the steps of heating a throat region of the barrel to between 170° C. and 190° C. 
     
     
         36 . The method as claimed in  claim 35  further comprising the steps of heating a remaining region of the barrel to between 210° C. and 230° C. 
     
     
         37 . The method as claimed in  claim 36  further comprising the steps of heating the crosshead chamber to a temperature in the range of 210 20  C. to 230° C. 
     
     
         38 . The method as claimed in  claim 37  further comprising cooling an extruded barrier layer exiting the crosshead chamber via a plurality of cooling baths. 
     
     
         39 . The method as claimed in  claim 38  wherein the temperature of each cooling bath is maintained in the temperature range of between 20□c to 40° C. 
     
     
         40 . The method as claimed in  claim 31  wherein said barrier layer is Polyamide-12 modified with a flexibilising component. 
     
     
         41 . The method as claimed in  claim 40  wherein said flexibilising component is a liquid plasticizer. 
     
     
         42 . The method as claimed in  claim 41  wherein said plasticizer is N-butylbenzenesulphonamide (BBSA). 
     
     
         43 . The method as claimed in  claim 29  wherein said barrier layer comprises a barrier polymer layer. 
     
     
         44 . A method for providing a multi-layer flexible pipe for conveying a target fluid comprising the steps of:
 providing at least one barrier polymer layer of polyamide-12 (PA-12) for providing internal fluid integrity.   
     
     
         45 . The method as claimed in  claim 44  further comprising the steps of forming a variety of polyamide-12 material via a two stage process, the second stage of the two stage process including a step of introducing a salt of a weak acid in order to nullify acid formed during the first phase. 
     
     
         46 . A method as claimed in  claim 45  wherein said PA-12 layer comprises a layer of a PA-12 variety. 
     
     
         47 . (canceled) 
     
     
         48 . (canceled)